Evaluation of desiccant wheel and prime mover as combined cooling,heating, and power system

In this research heating, cooling and electrical demands of a residential tower are evaluated for Iran various weather conditions. For this purpose, several cities are selected as the representative of the specific weather conditions. To meet the cooling demand, desiccant cooling system plus alternative systems are applied. To analyze desiccant wheel, outlet humidity and temperature have been modeled. Also, the effect of rotational speed and regeneration temperature on entropy generation of the desiccant wheel has been studied based on the obtained results. It is deduced that the entropy generation may be increased by increasing the regeneration temperature and the rotational speed. To regenerate the desiccant wheel, to meet the electrical demand and also to provide heating load, prime mover in the form of internal combustion engine is selected. Since prime movers do not operate in the full load, their performance in the partial load has been evaluated. By taking into consideration the required regeneration heating, the number of required prime movers has been calculated based on the regeneration temperature and partial load for each city. The results show that the number of required prime movers is increased by increasing the regeneration temperature of the wheel.     

Global Warming Impact of Electricity Generation from Beef Cattle Manure: A Life Cycle Assessment Study

We compare calculated greenhouse gas emissions for a North American beef feedlot operation, which includes biogas production by anaerobic digestion with subsequent electricity generation (the AD case), to the emissions for a “business as usual” case, which includes both a feedlot and an equivalent amount of grid-generated electricity. Anaerobic digestion, biogas production and electricity production are the major sources of differences in emissions. Fertilizer production, crop production, manure collection and spreading, as well as the associated transport stages are also considered within the LCA system boundaries; impacts on life cycle emissions from these sources are lower. Running a feedlot and producing electricity using typical grid power plants produces 3,845 kg CO_2?eq/MWh while running a feedlot, which generates biogas to produce electricity, produces 2,965 kg CO_2?eq/MWh. This savings of 880 kg CO_2?eq/MWh arises because the net power generation in the AD case emits about 90% less life cycle GHG emissions compared to grid-average electricity. The high overall emission levels arise due to emissions associated with enteric fermentation in beef cattle as the main source of GHG emissions in both the “business as usual” and the AD cases. It contributed 57% of total emissions for the feedlot /biogas /electricity system and 44% of total emissions for the feedlot /grid electricity system.     

Triple-objective optimal sizing based on dynamic strategy for an islanded hybrid energy microgrid

A triple-objective optimal sizing method based on a dynamic strategy is presented for an islanded hybrid energy microgrid, consisting of wind turbine, solar photovoltaic, battery energy storage system and diesel generator. The dynamic strategy is given based on a dynamic complementary coordination between two different master-slave control modes for maximum renewable energy utilization. Combined with the proposed strategy, NSGA-II-based optimization program is applied to the sizing optimization problem with triple different objectives including the minimization of annualized system cost, the minimization of loss of power supply probability and the maximization of utilization ratio of renewable energy generation. The sizing results and the proposed strategy are both compared and analyzed to validate the proposed method in a real case of an islanded hybrid energy microgrid on Dong’ao Island, China.     

单纯形最优化法在流动注射-氢化物-石墨炉原子吸收法测定海水中有机锡中的应用

用单纯形最优化方法对流动注射-氢化物-石墨炉原子吸收法测定海水中有机锡的条件进行优化，计算简便，用较少的实验次数动态地调至最佳分析条件。     

沈阳市老虎冲垃圾填埋场填埋气产量估算

通过选取3种不同的填埋气预测模型：IPCC模型、中国填埋气估算模型、德国模型,结合沈阳市老虎冲填埋场的实际情况,对各参数进行了修订,从而预测老虎冲填埋场填埋气产量情况,并分析比较各模型预测结果。结果表明,2003—2011年,3种模型反映了相同的填埋气变化趋势,趋于上升状态;2012—2025年,由于填埋量发生变化,IPCC模型与中国填埋气估算模型和德国模型的填埋气变化情况相反,呈下降趋势。3种模型预测的填埋气产量的峰值大小为：中国填埋气估算模型为3.3×107m3/a,IPCC模型为2.1×107m3/a,德国模型为9.8×106m3/a。根据实际产气情况进行对比,发现德国模型更符合实际情况。     

工业污染源产排污系数编码方法与应用

编码是将文字信息转换为计算机编程代码的重要工具。为进一步推进工业污染源产排污系数信息化应用,以2017年版产排污系数为核心,根据产排污系数结构及表达方式,建立工业污染源产排污系数编码体系,分别对产污系数和排放量核算参数两部分进行编码。产污系数编码是对表征产污系数的关键因素进行编码,包括行业类型、产污工段、产品、原料、工艺、规模、污染物种类等。排放量核算参数编码是对污染治理技术和治理设施运行效率分别进行编码。再根据各项关键因素的特征、包含信息种类数以及预留一定开发空间等条件,设定编码组成和位数,建立编码方案,并以“3825光伏设备及元器件制造行业”为例进行编码方案应用。产污系数编码为22位,排放量核算参数编码为28位或更多位。产排污系数编码体系的建立为搭建产排污系数信息平台,支撑系数持续更新完善,实现应用于更多环境管理系统提供直接技术支撑。     

生活垃圾焚烧副产物产生源特征

焚烧在我国某些城市逐渐开始成为主要的生活垃圾处理方式之一,同时,焚烧过程产生的副产物的二次污染及其性质渐受关注。本研究选取某典型生活垃圾焚烧发电厂,经过2年多在不同季节的多次取样,对其贮坑沥滤液、炉渣以及飞灰的产生状况及污染特性进行了分析,并着重讨论了垃圾中重金属在焚烧厂各股物流中的分布。     

在氧化沟中构建微生物燃料电池

在氧化沟中构建了微生物燃料电池,经测定微生物燃料电池电压为0.24～0.39 V,均值为0.29 V.经计算该微生物燃料电池的产电功率为0.05～0.15 mW,均值为0.08 mW.构建了微生物燃料电池的氧化沟COD去除率为75％～ 90％,TN去除率为5％～38％;无微生物燃料电池的氧化沟COD去除率为77％～89％,TN去除率为5％～23％.构建微生物燃料电池后能减少氧化沟内外沟中污泥的增加量,约减少15％.     

四川省秸秆综合利用困局及对策建议

以四川省为例,分析了秸秆综合利用中5个方面的问题,提出了相应的3点对策和建议。     

北京市工业危险废物产生特性研究

根据对部分企业的实地调查数据、北京市有关单位在2003年的调查数据、2003年北京市企业排污申报登记数据、2003年部分企业危险废物转移联单数据以及结合2001年北京市排污申报登记数据,全面分析了北京市工业危险废物产生总体特性.这些特性包括危险废物的产生量和去向,区域和行业分布特点,产生量与工业总产值的关系等.同时,根据北京百万元产值危险废物产生量进行了预测,结果表明到2010年,北京市危险废物产生量将达到近19.5万吨.